IS bride Shamima Begum’s baby has reportedly died after being rushed to hospital with a lung infection.

The 19-year-old UK-born teenager and her newborn Jarrah had recently been living at a desert refugee camp after being told she had been stripped of her British citizenship.

She left her London home to join the Islamic State group in Syria.

Her lawyer said the boy was reported to have died.

Lawyer Tasnime Akunjee tweeted that he has “strong but as yet unconfirmed reports that Begum’s son has died. He was a British citizen.”

He declined to provide further details.

However, Mustafa Bali, spokesman for the military group in northern Syria, the Syrian Democratic Forces, tweeted that the reports were “fake” and the baby “is alive and healthy.” The British government could not confirm the reports.

Begum was 15 when she and two friends left London to marry IS fighters in Syria in 2015, at a time when the group’s online recruitment program lured many impressionable young people to its self-proclaimed caliphate.

Begum recently resurfaced in a refugee camp, and gave birth last month.

Begum, now 19, told journalists that she wanted to raise her son in Britain, but the government revoked her citizenship.

Begum told reporters that she had lost two other children to malnutrition and disease.

Her Dutch jihadi husband Yago Riedijk, who is in a Kurdish-run detention centre, said last week that he wanted to return to the Netherlands with Begum and their son.

British Home Secretary Sajid Javid said last month he had revoked Begum’s citizenship — even while saying he wouldn’t make a decision that would render a person stateless. Javid also confirmed that Begum’s son was a British citizen, though he said it would be “incredibly difficult” to facilitate the return of a child from Syria.

Begum’s parents are from Bangladesh but her family says she isn’t a dual citizen. The family has said it plans to challenge Javid’s decision.

The news comes as Begum’s father said his daughter’s citizenship should not be revoked and that she should return to the UK and be punished if it was determined she had committed a crime.

Begum’s father, Ahmed Ali, told The Associated Press in an interview in his Bangladeshi village that he would still request that the British government allow his daughter to come back.

“My child was only 15 years old when she fled, she was immature,” said Ali, who lives in the northeastern Bangladeshi district of Sunamganj with his second wife. The area is 181 kilometres (112 miles) northeast of Dhaka, the capital. “I would ask the British government not to cancel her citizenship, to return her citizenship, and if she is guilty, bring her back to Britain and give her punishment there,” he said.

Ali, 60, said he moved to England in 1975 and returned to his village in Bangladesh in 1990 to marry his first wife, Asma Begum. The couple, who returned to England, has four daughters, with Shamima the youngest.

Ali later returned to Bangladesh and got married for a second time. Most recently, he came to Bangladesh two months ago to escape the UK winter. Ali criticised the British authorities for failing to properly deal with the issue of students who have fled to join the IS.

“One girl went there a month ago, most likely a month ago. The British government should have been alarmed about the matter, and they should have also inquired at the school to find out how she fled, since she was a student,” he said. “Then a month later, three more students fled. The authorities should investigate at the school why these students fled. They were not adults.” “The British immigration system is very informed, the most informed system in the world. I always say how did (Shamima) get there using another one’s passport? She doesn’t even have her own passport. These matters should be investigated as well,” Ali said.

His daughter’s husband, Yago Riedijk, 27, told the BBC this month from a Kurdish-run detention centre that he met Begum within days of her arrival in Syria when she was 15. He said the marriage was “her own choice.”

When asked if marrying a 15-year-old was appropriate, Riedijk said: “To be honest, when my friend came and said there was a girl who was interested in marriage, I wasn’t that interested because of her age, but I accepted the offer anyway.” Riedijk said that while he fought for IS, he now rejects the group and tried to leave it.

While it’s unclear if Begum has committed a crime, her comments — and those of her husband — throw into sharp relief larger questions about how Western societies will deal with others who joined IS but want to return to their home countries now that the extremist group is on the verge of collapse.